1BadBrd

What is the best way to correct know. If it says
RPMs: 3600
Spark Adv.: 28
Spark Ret.: 11
MAP: 75 KPa

Do i adjust the spark advance ? Would i adjust -11? I just started to lower the advance by 1 to see what happens, but my clutch went out so while i wait to get time in the garage, i wanted to ask this question.
Plus how much should i worry about .5, .8 degrees of retard.

Dan K

Still can't get that thing running well huh?
I'd love to see that Ed Wright file compared to the one I sent you.

Take timing out at that map and rpm if the computer is retarding timing.
Was this WOT?
BTW, you should tune for no knock.

1BadBrd

Dan, i was worried, maybe pissed you off or something since i never got a respnce to the last email. Hope things are going good for you. The car runs like a champ now. There are only two maybe three points were i'm getting retard. I was curious what to do since the advance was at 28 and it said 11 degrees of retard, so bringing the advance down to 17 didn't sound right. I have one point that hits around 5 degrees retard and one that is around 10 degrees and a couple little ones that spike no further then .5-.9 degrees retard.

I do beleive that the retard was at WOT.

I would love to see the Ed Wright file myself just to see what $300 got me.

Like i said putting the retard that low didn't sound right.

Soma07

MAP usually hits 100 pretty quick at WOT so you weren't quite there but pretty close.

I would pull out 2 degree's of timing in the area's where you're getting KR then retest. The PCM is very conservative so it pulls out ALOT of timing when it detects KR.

You could also be runnnig lean at those points which could induce knock as well. But you really have no way of knowing if you are or arent without a wideband O2 sensor.

jgeorger

The first thing you need to do is determine if your knock is real. Chances are it's not. You can do this by putting some 100 octane gas in (do not use octane boosters as they are falsely advertised. If you still get the knock it's false.

You also didn't mention if you were wot when you reported your data. 75 kpa is a good load but can be hit without going wot.

My car was getting buttloads of knock at part throttle - I assumed it was false and zeroed out all the spark retard tables. Car ran noticeably better, with no pinging or knocking.

Even with an LT4 KM, roller rockers, headers, aftermarket plug wires, and lugging a cammed car all contribute to false knock.

Joe

Injuneer

I'm assuming the "it" above is a scanner. If so, most of them report the timing the PCM is calling for, which is the programmed value minus the retard. So, it appears that at 3,600rpm/75kPa your PCM is programmed for 39deg advance, and the PCM is pulling 11deg in response to a signal from the KS, right or wrong.

As noted in the posts above, before you start altering the timing, find out if the knock is real or false. If its real, correct the source of the problem, which may be excessive timing, or might be poor quality fuel, excessive coolant temp, excessive inlet air temp, carbon buildup, etc.

If you were just to pull 11deg timing out of the program, you would just reduce performance all the time to the levels the "retard" is causing you now.